Three-dimensional map construction is the core technology for environment perception. For example, when adding an object to a augmented reality (AR) scene, it is necessary to acquire the true scale of the object from the three-dimensional map corresponding to the scene. At present, usually it is necessary to use specific equipment such as binocular cameras and depth cameras to construct a three-dimensional map in which each object corresponds to the true scale.
However, on commonly used terminals such as mobile phones and tablet PCs, only monocular cameras are provided. It is not possible to construct a three-dimensional map in which each object corresponds to the true scale.